Sejanus

Lucius Aelius Sejanus was a soldier who became the right hand man of the Emperor Tiberius (14-37 CE).
He served as Prefect of the Praetorian Guard between 15-31 CE.

Sejanus’ father Strabo, was Prefect of the Praetorian Guard until 15 CE when he became Prefect of Egypt.
In 14 CE when the Legions on the Rhine mutinied, Sejanus and Drusus were sent to Germany. The Legions were persuaded to remain loyal by Drusus, whilst the ringleaders were executed by Sejanus.

In 14 CE Sejanus saved Tiberius‘ life, by extracting him from a collapsed grotto at his country retreat, the Villa of Tiberius at Sperlonga.
Tiberius elevated him and considered him to be a close friend and his right hand man, like his father Strabo.
In 15 CE Sejanus became Prefect of the Praetorian Guard until his execution in 31 CE.
Whereas Augustus had kept the Praetorian Guard discreet, by dispersing the 9 Cohorts across the City and surrounding towns, Sejanus concentrated them into the new Castra Praetoria and expanded them to 12 Cohorts, about 12,000 men.
The Republican ideals and the Roman Senate were now clearly subordinate to this armed presence. Sejanus dispensed with the two Prefects system, concentrating all power in himself, and made all the appointments of Praetorian Officers and Centurions.
Sejanus seems to have created the Delatores, who are mentioned for the first time during Tiberius‘ Rule. These were professional Informers who reported on Opponents of the State and testified against them at their Treason Trials.
By 23 CE, statues of Sejanus were erected around Rome, his friends in the Roman Senate were promoted to Governorships or became Magistrates, and unusually for an Equestrian, he was promoted to Praetor.

Tiberius’ son Drusus, although the named heir, was sidelined by Sejanus’ growing power. The two men had open disagreements in public.
In 20 CE Sejanus tried to tie himself into the Julian Family, by betrothing his 4 year old daughter to Claudius‘ son, who unfortunately died of asphyxiation, preventing the marriage.
In 22 CE Tiberius shared power with Drusus by sharing his powers as Tribune.
Sejanus had become the lover of Drusus’ wife, Livilla, and used her to slowly poison Drusus.
In 23 CE Drusus died, apparently of natural causes.

In 19 CE Germanicus, named heir of Augustus whilst based in Syria with his family, died in mysterious circumstances.
Germanicus’ wife, Agrippina the Elder, who had unusually, accompanied her husband with the family and lived with him at his Legionary headquarters. She returned to Rome with her six children, and openly campaigned with a group of Senators to oppose Sejanus. She advised Tiberius, Sejanus had been responsible for Germanicus’ death, through Piso, the Governor of Syria, who was forced to commit suicide. In 23 CE, her three sons, Nero Caesar, Drusus Caesar, and Caligula were all in line to become Emperor after Tiberius’ son, Drusus.
This pushed Sejanus into a second attempt to join the Julian Family by requesting marriage with Drusus’ widow and Claudius‘ sister, Livilla, which Tiberius refused on the basis that he was only an Equestrian.
This piqued Sejanus into action, he now became ruthless.

In 26 CE Sejanus persuaded Tiberius to retire permanently to Campania and his villa on the Island of Capri, to avoid all the Court intrigue. Sejanus was already running the Empire on Tiberius‘ behalf, whilst Tiberius had been taking longer and longer holidays in Campania. As his bodyguard was the Praetorian Guard all information he sent and received was controlled by Sejanus, who was now free to eliminate his enemies.

In 29 CE Tiberius’ mother, Livia Drusilla who had acted as a restraining force on Sejanus, died in Rome. This prompted Sejanus to eliminate his enemies.
Sejanus used his intelligence network and the ‘Delatores’ to organise and make false accusations of Treason in Show Trials against Senators and Equestrians who had opposed him.
Gaius Asinius Gallus was Tried and died in Prison of starvation. A Senator, he had been an opponent of Tiberius and ally of Agrippina the Elder. He was also the husband of Tiberius‘ first wife, Vipsania Agrippina (who had died in 20 CE), whom Tiberius had been forced to divorce to marry Augustus‘ daughter Julia the Elder.
The other Senators and Equestrians committed suicide before they could be tried.
In 30 CE Agrippina the Elder was arrested with two of her sons, Nero and Drusus and Exiled. They both died of starvation. Caligula survived by moving into Tiberius’ villa on Capri in 31 CE.
Sejanus was now ‘De Facto’ Ruler of the Roman Empire. He had eliminated his enemies, he controlled the Roman Senate and finally became engaged to Livilla.

Roman Historians disagree over what exactly triggered Sejanus’ demise.
In 31 CE, Livilla’s mother sent a message to Tiberius in Capri, bypassing the Praetorian Guard by sending her personal servant with a despatch.
According to Juvenal, a despatch was sent from Capri to execute Sejanus without Trial. Dio Cassius also gives a detailed description of Sejanus’ fall.
Sejanus was arrested, executed and his body thrown down the Gemonian Stairs.